-Purpose. Amyotrophic lateral sclerosis is a fatal neurodegenerative disease characterized by the loss of motorneurons. The only drug approved is riluzole. Minocycline is an antibiotic with numerous neuroprotective properties. riluzole and minocycline were given to an animal model of ALS and had beneficial effect on the disease. The combination was then tested in humans in phase II and phase III studies with less beneficial effects and a faster decline of the disease in the group treated with minocycline. In a previous study, we showed that riluzole is transported out of the brain by the P-glycoprotein at the bloodbrain barrier level. In this work, we tested the hypothesis of a drug-drug interaction between riluzole and minocycline. Methods. We studied in CF1 mice, the plasma and brain pharmacokinetics of riluzole combined or not with minocycline. Results. Our results showed that riluzole pharmacokinetics are not linear with dose, but that brain AUC 0-t increase proportionally with plasma AUC 0-t . At the dose of 10 mg/kg, the brain AUC0-t /plasma AUC0-t ratio was 4.6 in mdr1a (-/-) mice and 2.4 in mdr1a (+/+) mice. The combination of minocycline (170 mg/kg) and riluzole (10 mg/kg) induced a 2 fold increase in the brain AUC0-t of riluzole and induced a neuromuscular toxicity in mice. This effect of minocycline was not found at low concentration (10 mg/kg of minocycline). Conclusions. If our results are confirmed in humans, riluzole brain concentrations could be predicted by plasma concentrations. Furthermore, the combination of high doses of minocycline with riluzole could induce neurological toxicity that lead to deceiving results in ALS clinical studies. Hence, a dose-range of minocycline combined with riluzole should be tested in further clinical studies.

This work reports the biocompatibility evaluation of cyclic olefin copolymers (COC) as candidates for implantable medical devices. The focus was to establish the influence of two major additives (antioxidant and lubricant) on the overall biocompatibility. The cytotoxicity was evaluated according to ISO 10993-5 guidelines using L929 fibroblasts, HUVEC, and THP-1-derived macrophages. Oxidative stress (ROS, GSH/GSSG, and SOD analysis) and pro-inflammatory cytokines (Il-6 and TNF-α secretion) were quantified using THP-1 cells in direct contact with films. Hemocompatibility was assessed through haemolysis testing, dynamic blood coagulation, platelet adhesion, and activation (membranous P-selectin expression). Results show that the different types of COC have successfully passed the in vitro biocompatibility tests. The presence of antioxidant induces however a slight decrease in ROS production in correlation with a high SOD activity and a modification in blood coagulation profile probably linked to antioxidant recrystallization phenomenon on the surface of COC. The lubricant presence reduced haemolysis, fibrinogen adhesion, and platelet activation. Surface nanotopography of COC highlights different types of needles and globules according to the present additive. Those primary results indicate that COC are promising biomaterial. However, additives influenced some biological parameters pointing out the necessity of a global approach of risk analysis for biocompatibility evaluation. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3333-3349, 2017.

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